i want to have the sketch origin is always placed at the origin of projected part position.
I have much troubles with loosing constraint of the sketch origin.

The sketch origin is placed somewhere to an edge of the sketchplane but not comprehensible. So when you place a new features afterwards in history tree before the sketch than mostly loosing the reference and have to do a lot of rework.
It´s not always but very often. So if the sketch origin is placed to projected part origin you can´t loose constraint because part origin is always there and can´t be deleted.